Fix #700 #701: JSONC tsconfig parsing + Svelte dynamic import edge IDs

#700: _read_tsconfig_aliases() now handles // comments, /* */ block comments,
and trailing commas via a regex-based _strip_jsonc() helper. Tries plain
json.loads first, falls back to stripped parse, warns to stderr on failure
instead of silently returning {}.

#701 Bug A: removed startswith('.') filter from Svelte regex fallback so
aliased imports ($lib/, $partials/, @/) are no longer skipped.
#701 Bug B: fixed synthetic node IDs — source uses _make_id(str(path)),
target uses _make_id(str(normpath(parent/raw))) matching _extract_generic
and _import_js conventions so build_from_json no longer drops every edge.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

graphify/extract.py

@@ -48,18 +48,59 @@ def _file_stem(path: Path) -> str:
 _TSCONFIG_ALIAS_CACHE: dict[str, dict[str, str]] = {}
 
 
+def _strip_jsonc(text: str) -> str:
+    """Strip // line comments, /* */ block comments, and trailing commas from JSONC.
+
+    Preserves string contents (including // and /* inside strings) by skipping over
+    quoted spans first. Required for tsconfig.json files generated by SvelteKit,
+    NestJS, Vite, T3, Astro, etc., which use JSONC by default (#700).
+    """
+    # Remove block and line comments while leaving string literals untouched.
+    pattern = re.compile(
+        r'"(?:\\.|[^"\\])*"'    # double-quoted string (with escapes)
+        r"|/\*.*?\*/"           # /* block comment */
+        r"|//[^\n]*",           # // line comment
+        re.DOTALL,
+    )
+
+    def _replace(match: re.Match) -> str:
+        token = match.group(0)
+        if token.startswith('"'):
+            return token
+        return ""
+
+    stripped = pattern.sub(_replace, text)
+    # Remove trailing commas before } or ] (allowing whitespace between).
+    stripped = re.sub(r",(\s*[}\]])", r"\1", stripped)
+    return stripped
+
+
 def _read_tsconfig_aliases(tsconfig: Path, base_dir: Path, seen: set) -> dict[str, str]:
     """Recursively read path aliases from a tsconfig, following extends chains.
 
     Child config paths override parent. Circular extends are detected via seen set.
     npm package configs (e.g. @tsconfig/svelte) are skipped since they're not on disk.
+    Handles JSONC (comments + trailing commas) which is the default tsconfig format
+    for SvelteKit, NestJS, Vite, T3, Astro, etc. (#700).
     """
     if str(tsconfig) in seen:
         return {}
     seen.add(str(tsconfig))
     try:
-        data = json.loads(tsconfig.read_text(encoding="utf-8"))
-    except Exception:
+        raw = tsconfig.read_text(encoding="utf-8")
+    except Exception as e:
+        print(f"  warning: could not read {tsconfig} ({type(e).__name__}: {e})", file=sys.stderr, flush=True)
+        return {}
+    try:
+        data = json.loads(raw)
+    except json.JSONDecodeError:
+        try:
+            data = json.loads(_strip_jsonc(raw))
+        except json.JSONDecodeError as e:
+            print(f"  warning: failed to parse {tsconfig} as JSON/JSONC ({e.msg} at line {e.lineno} col {e.colno})", file=sys.stderr, flush=True)
+            return {}
+    except Exception as e:
+        print(f"  warning: failed to parse {tsconfig} ({type(e).__name__}: {e})", file=sys.stderr, flush=True)
         return {}
 
     aliases: dict[str, str] = {}
@@ -1708,13 +1749,50 @@ def extract_svelte(path: Path) -> dict:
         import re as _re
         src = path.read_text(encoding="utf-8", errors="replace")
         existing_ids = {n["id"] for n in result.get("nodes", [])}
-        file_node_id = _make_id(path.stem, str(path))
+        # Source file node ID must match the one _extract_generic creates:
+        # _make_id(str(path)) - single arg, no stem prefix. Otherwise the source
+        # endpoint is a phantom node and build_from_json drops the edge (#701).
+        file_node_id = _make_id(str(path))
+        aliases = _load_tsconfig_aliases(path.parent)
         for m in _re.finditer(r"""import\(\s*['"]([^'"]+)['"]\s*\)""", src):
             raw = m.group(1)
-            if not raw.startswith("."):
+            if not raw:
                 continue
-            node_id = _make_id(raw, str(path))
+            if raw.startswith("."):
+                # Relative import - resolve to full path so IDs match file node IDs.
+                resolved = Path(os.path.normpath(path.parent / raw))
+                # TypeScript ESM: imports written as .js but actual file is .ts/.tsx
+                if resolved.suffix == ".js":
+                    resolved = resolved.with_suffix(".ts")
+                elif resolved.suffix == ".jsx":
+                    resolved = resolved.with_suffix(".tsx")
+                node_id = _make_id(str(resolved))
+            else:
+                # Check tsconfig.json path aliases (e.g. "$lib/" -> "src/lib/", "@/" -> "src/")
+                # before treating as external. Mirrors _import_js logic so SvelteKit alias
+                # imports resolve to the same file node IDs the extractor creates (#701).
+                resolved_alias = None
+                for alias_prefix, alias_base in aliases.items():
+                    if raw == alias_prefix or raw.startswith(alias_prefix + "/"):
+                        rest = raw[len(alias_prefix):].lstrip("/")
+                        resolved_alias = Path(os.path.normpath(Path(alias_base) / rest))
+                        break
+                if resolved_alias is not None:
+                    node_id = _make_id(str(resolved_alias))
+                else:
+                    # Bare/scoped import (node_modules) - use last segment;
+                    # build_from_json drops as external if no matching node exists.
+                    module_name = raw.split("/")[-1]
+                    if not module_name:
+                        continue
+                    node_id = _make_id(module_name)
             if node_id in existing_ids:
+                # Edge target already a real node - just add the edge, don't add a node.
+                result.setdefault("edges", []).append({
+                    "source": file_node_id, "target": node_id,
+                    "relation": "dynamic_import", "confidence": "EXTRACTED",
+                    "source_file": str(path),
+                })
                 continue
             result.setdefault("nodes", []).append({
                 "id": node_id, "label": raw,